Answer in brief
CVE-2026-75834 records a Medium severity (CVSS 5.4) vulnerability in Grav before 2.0.14 Stored XSS via Invalid UTF-8 Byte. The current sources do not mark it as known exploited. The current feed maps getgrav/grav (composer), getgrav/grav (generic), getgrav/grav (packagist). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.4. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps getgrav/grav (composer), getgrav/grav (generic), getgrav/grav (packagist). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| getgrav/gravcomposer | <2.0.14 | 2.0.14 |
| getgrav/gravgeneric | >=0 <2.0.14 | 2.0.14 |
| getgrav/gravpackagist | >=0 <2.0.14 | 2.0.14 |
Published upstream
Aug 18, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 18, 2026
Grav before 2.0.14 contains a stored cross-site scripting vulnerability in the Security::detectXss() function (system/src/Grav/Common/Security.php). All XSS detection patterns use the PCRE /u (UTF-8) modifier, so a single invalid UTF-8 byte anywhere in page content causes preg_match() to return false for every pattern, silently bypassing the save-time XSS safety gate (Validation::checkSafety()). An authenticated attacker with page-edit permissions (without the security.xss_whitelist privilege) can store malicious JavaScript that executes in the browser of a visitor who views the affected page.
Quoted source text, attributed separately from HOL analysis.